Superman, the guy who gets Batman to work with the Justice League... you think he's *not* a Hufflepuff? He's all about hard work, doing the job that needs doing, and good sense (http://imadra-blue.livejournal.com/39371.html).

Wonder Woman is a bit of a harder stretch, but she's also a good team-builder and more about working together for a better future instead of beating shit out of people because their stupidity is pissing her off.